In the fabrication of semiconductor devices, the devices are tested before shipment to ensure correct operation and performance at different temperatures. For this testing, the temperature is carefully controlled to ensure that the device operates correctly under varying cooling and processing loads (silicon heat dissipation). These testing procedures use a thermal control unit that has a temperature-controlled surface for contacting the electronic component being tested. By changing the temperature of this surface, different temperatures and different amounts of cooling can be achieved.
A liquid thermal interface material is used between the thermal control unit surface and the electronic component. The thermal interface material is used to improve the heat flow between the surface and the electronic component. In other words, the thermal interface fluid (IF), also referred to as a liquid thermal interface material (LTIM), reduces thermal contact resistance. The liquid is applied and removed for each component to be tested. The fluid leaves some residue on the thermal control surface which is cleaned as regular maintenance.
The thermal tests may also be used to trim digital temperature sensors and to minimize the temperature rise in silicon transistor junction. In some electronic components, the temperatures sensors are used to trigger the operation of cooling fans and to throttle the operating speed of the component to prevent overheating.